1. Field of the Invention
The present invention relates to an optical information recording/regenerating apparatus of a multi-track regeneration type and a track scanning method for an optical information recording/regenerating apparatus that can scan and regenerate multiple tracks on an optical recording medium such as an optical card simultaneously.
2. Description of the Related Art
Multiple parallel tracks having inherent addresses are running on an optical recording medium such as an optical card.
In an optical information recording/regenerating apparatus, information recording or regenerating is achieved by reciprocating an optical recording medium and an optical head relatively to each other in a direction parallel or perpendicular to tracks. For recording information on an optical recording medium, an error-correcting code is appended to information to be recorded, and the information is recorded as a pit in a track using a modulated optical beam. For regenerating recorded information, a regeneration light spot is irradiated to a track to be regenerated, the presence or absence of a pit is detected depending on the intensity of reflected light, and then demodulation and error correction are performed. Finally, the recorded information is regenerated. If error correction fails, retry is performed in general.
In this kind of optical information recording/regenerating apparatus of a single-track regeneration type, an executable regeneration speed for information per a track is determined by a relative speed between an optical head and an optical recording medium but does not exceed the relative speed.
As a solution of this problem, an optical information recording/regenerating apparatus of a multi-track regeneration type has been proposed. This apparatus irradiates regeneration light to multiple tracks simultaneously, has regeneration light-receiving elements in one-to-one correspondence with tracks, detects recorded pits in multiple tracks side by side simultaneously, and then regenerates information. For example, an apparatus disclosed in Japanese Patent Laid-Open No. 2-141932 samples binary-coded signals, which derive from pit detection signals acquired from tracks, using high frequencies, stores the binary-coded signals in memories associated with the tracks, and then reads the sampled binary-coded signals from the memories for regeneration.
This kind of optical information recording/regenerating apparatus of a multi-track regeneration type utilizes the advantage that reading the data of one track from a memory is much faster than actually scanning one track.
When a track to be regenerated is one of multiple tracks scanned previously, regeneration scanning need not be done but data is read from a memory to regenerate information. Compared with the single-track regeneration type, the multi-track regeneration type permits a higher executable regeneration speed.
However, Japanese Patent Laid-Open No. 2-141932 does not mention a track access method. That is to say, an effective track scanning method has not been discussed in terms of a track for which error correction has failed during information regeneration.